In a conventional glass sheet press bending system, a glass sheet is heated in a glass sheet heating furnace to its bending temperature and deposited onto a first shaping surface of a mold, be it a perimeter ring mold or full face mold, for subsequent bending. Then the heated glass sheet and mold are immediately shuttled to a bending location where a cooperating second shaping surface on another mold is brought into contact with the glass sheet on the first shaping surface to conform the glass sheet to the shape of the shaping surfaces.
The molds are mounted on supports which are movable toward each other along a fixed path by mechanical actuators. As this tooling undergoes expansion due to heating and contraction due to cooling in the bending environment, some relative rotational and/or translational movement occurs between the shaping surfaces of the molds. More specifically, the conventional actuators do not correct the shaping surface alignment between the molds as the tooling is heated and cooled during production bending. Therefore an operator must compensate for mold misalignments during production bending resulting in lost production time.
Furthermore, conventional glass sheet shaping tool changes generally require 7-10 hours of down time to effect a change to a new tool. This entails 3-4 hours of cool down time plus another 2-3 hours of labor time plus 2-3 hours of furnace section heat-up time. This too results in lost production time.